| Abraham Lincoln | 1809–1865 (KY) | 1861–1865 | Hamlin, Johnson | Practiced law in Springfield; built political career in IL | Preserved Union; Emancipation Proclamation |
| Ulysses S. Grant | 1822–1885 (OH) | 1869–1877 | Colfax, Wilson | Lived in Galena; Illinois support before Civil War | Won Civil War; led Reconstruction policies |
| Barack Obama | 1961– (HI) | 2009–2017 | Joe Biden | IL State Senator & U.S. Senator; Chicago political rise | Affordable Care Act; Osama bin Laden operation |
| Ronald Reagan | 1911–2004 (IL) | 1981–1989 | George H.W. Bush | Born/raised in Illinois; Dixon & Monmouth ties | Cold War momentum shift; economic policy (“Reagan Revolution”) |